The polishing device is so constituted that while a surface table for polishing is rotated, a work such as a semiconductor wafer is mounted on a polishing head provided opposite the surface table so as to be rotated, the surface of the work is pressed against the surface of the surface table, and the polishing head is moved radially of the surface table, thereby polishing the entire surface of the work more uniformly.
In the conventional polishing device, the polishing head is fitted to a swing arm for up and down motion, and is moved up and down by means of a lifting drive secured to the swing arm, while a force pressing the work against the surface table is controlled. Rotation of the polishing head is given by way of a rotation transmitting mechanism such as a belt or the like which also serves as a reduction mechanism, from a motor provided on the swing arm or a frame to which the swing arm is secured. Rotation of the surface table and swing of the swing arm are performed by way of a reduction and rotation transmitting mechanism such as a belt or gears from a motor.
The construction of the polishing head being fitted to the swing arm for up and down motion, has a disadvantage in that since the relative movable parts are positioned near the surface table, there is a high possibility of the work such as a semiconductor wafer or the like being contaminated by dust produced due to wear of the metal, and also from a view point of the entire device, it has a disadvantage in the production of dust being apt to be released in the air, thereby providing a high possibility of contaminating the surroundings.